A Review of Topologies and Control Methods for Single-Phase Grid-Connected Solar Inverters

Abstract

Since fossil fuels cannot keep up with the world's rising energy demands, solar photovoltaic (PV) systems offer a clean, pollution-free, and dependable alternative renewable energy source. So, the need for solar PV grid connected inverter systems are gaining more importance and emphasis is given to develop and design grid connected inverters with low cost, size, weight, highly reliable and efficient topologies. This review paper presents the evolution of inverter technologies, inverter topologies, with transformer or transformerless system. The key topologies, including H-bridge variants and multilevel structures, are compared based on parameters like efficiency, leakage current, and total harmonic distortion (THD). The various control strategies, encompassing maximum power point tracking (MPPT), pulse-width modulation (PWM), and current control methods like proportional resonant (PR) are presented for performance under varying grid conditions. A single phase full bridge inverter model is prepared and simulated in Matlab. The effect of variation of irradiance and temperature on the generated output power, voltage and current is measured. Also, the output current is of sinusoidal nature and the THD of 1.04% is analyzed using the FFT tool of Matlab.